Well, the --with-x=no would really only eliminate the dependencies on:
libSM.so.6()(64bit)
libX11.so.6()(64bit)
libXmu.so.6()(64bit)
libXt.so.6()(64bit)
Thanks to modular X, those dependencies are really small.
But what you're really noting is that we're hardcoding a Requires for evince and
firefox, because we need to define R_PDFVIEWER and R_BROWSER for the R build.
We could make an alternate R package that sets R_BROWSER to links, but I'm not
sure what non-graphical PDF viewer we could set for R_PDFVIEWER. I suppose we
could leave it entirely unset.
Let me poke this for a bit and see what I can come up with.